Core sampler



CORE SAMPLER Filed July 27, 1966 2 2 i 22 mun-2:1;

, FIG. 5.

INVENTOR. ANDRE M. ROSFELDER BY FIG. 4. Z

ATTORNEY.

United States Patent 0 3,383,131 CORE SAMPLER Andre M. Rosfelder, LaJolla, Calif., assignor, by mesne assignments, to the United States ofAmerica as represented by the Secretary of the Navy Filed July 27, 1966,Ser. No. 568,359 10 Claims. (Cl. 294-69) ABSTRACT OF THE DISCLOSURE Thedescription discloses a tubular core sampler which utilizes a flexibletube at its lower end for closing such end when a core sample has beenobtained. The closure is effected by twisting the flexible tube untilthe tube constricts any passage. The twisting action may be accomplishedby a torsion spring which is connected at its ends to the respectiveends of the tube. The spring is held in a biased condition with theflexible tube open until such time that closure is desired, whereuponthe spring is released to twist the flexible tube for closure purposes.

The present invention relates to a closure valve and more particularlyto a core retaining closure valve for use in combination with anunderwater core sampler.

Underwater exploration has been under study for many years in an effortto acquire more scientific information about the undersea environment.One of the standard tools of underwear exploration is a core sampler, adevice used to secure samples of the ocean bottom. While the use of coresamplers is not new, many diflicult problems have arisen in regard totheir use. Perhaps the most difficult problem has been the inability ofthe core sampler to retain the core once it has been secured,particularly in deep sea operations. The difficulties involved occur atvarious steps of the core sampling operation, for example: 1) after acore sample has been taken and removal of the core sampler started, asuction takes place at the bottom of the core sampler which tends toextract a part of the core; (2) if a small leak is present during ascentwater tends to wash the core sample away; (3) once the core sampler isbrought to the surface and before it is taken aboard ship, widefluctuations in the pressure due to wave actions and handling operationsoften cause the core to suddenly collapse occasioning a total loss ofthe core just moments before complete retrieval. Accordingly, in mostsampling operations it is necessary that a valve be employed to closethe bottom of the core sampler so as to retain the soil sample therein.

Prior art core valves or retainers may be divided into two categories.The first type is the oldest and most common and can be classed aspassive. Such retainers include finger springs which are devices thatare comprised of thin strips of metal adapted to bend in one directiononly so as to allow the core sample to enter the sampler tube whilepreventing its removal. A second such device is the flap valve. The flapvalve is simply a small hinged plate allowed to open by the pressure ofthe entering core sample and then biased shut by a spring means when thepressure ceases. In addition, there are many passive core retainerswhich are mounted externally of the core sampler. The disadvantages ofthe passive devices are that they do not always close or that theyinjure or damage the sample because of protrusions adjacent the insidewall of the core sampler. Some of the external core retainers haveproven to be too fragile for use.

The second category of core retainers, which seems to be moreextensively used as it is more efficient and allows for less disturbanceof the sample, can be classed as the dynamic type; this type relies onsome additional source of energy for closure during the initial removalfrom the ground. Some of these devices work as follows: an expandableweight may close a turnable valve, a flap valve may be actuated by awire leading to the surface vessel, or a rubber annular chamber may beexpanded by pumping fluid from the surface vessel; but all these dynamiccore retainers have the disadvantage of either being too complex anduneconomical or requiring some type of connection to the surface vessel.

The present invention overcomes the aforementioned disadvantages ofprior art closure valves and features a novel and very inexpensive coresampling closure valve which imposes a minimum of disturbance on thesoil sample and which may be adapted to effect automatic and tightclosure of the corer upon its withdrawal from the soil. The presentinvention has been accomplished by providing a core sampler with aclosure valve which comprises a flexible tube within the lower end ofthe core sampler which is capable of twisting to close the core sampler,a spring means adapted to twist the flexible tube to effect closure asthe spring translates from a biased to an unbiased condition, and meansfor retaining and then releasing the spring means from a biasedcondition when the core sampler is to be closed.

An object of the present invention is to provide a core sampler with aclosure valve which overcomes each of the aforementioned disadvantagesof prior art closure valves.

Another object is to provide a very inexpensive core sampler with aclosure valve which imposes minimum disturbance on the soil sample andis automatically actuated by upward withdrawal of the core samplerthrough the soil.

A further object is to provide a highly responsive and quick closingcore sampler with a closure valve which can be constructed with thinwalls so as not to obstruct the inner space of the core sampler nose andyet can be easily removed and replaced within the core sampler.

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered with the accompanying drawing wherein:

FIG. 1 is a side view of a core sampler in the ocean bottom.

FIG. 2 is a top section view of the valve shown in open position takenalong plane 22 of FIG. 1 or FIG. 4.

FIG. 3 is a top section view of the valve shown in closed position takenalong plane 3-3 of FIG. 5.

FIG. 4 is a section side view taken along plane 4-4 of FIG. 2; and

FIG. 5 is a section side view taken along plane 55 of FIG. 3.

Referring now to the drawing wherein like reference numerals designatesimilar or corresponding parts throughout the several views, there isshown in FIG. 1 a core sampler 10 which has been driven by its ownweight into the ocean bottom to secure a soil sample. The core sampler10 comprises a tubular corer 12 which receives the core sample, and aweight means 13 to provide negative buoyancy. The tubular corer 12comprises an outer tube 14, FIG. 4, within which is fitted a tubularliner 16 which may be constructed of a material such as plastic; theliner 16 with a core sample is removable from the outer tube 14providing a convenient method for handling and storing the core sampleuntil it is ready to be tested in the laboratory. The tubular corer 12has at its bottom end a soil cutter 18 which is threaded at its upperextreme to the bottom of the outer tube 14 so as to allow for easyremoval of the cutter in the event of breakage or in case the oceanbottom requires a different type of cutter. The closure valve is locatedat the lower end of the tubular corer 12 between the liner 16 and thecutter 18.

The closure valve comprises a flexible tube 20 which may be made ofnylon and is situated generally concentric with the inner surface of theouter tube 14 in a generally loose condition as shown in FIGS. 2 and 4when in an open position. As shown in FIG. 2, there are no protrusionswhich might damage a core sample and resistance to the sample is kept toa minimum. Thus, the core sample is received in substantially the samestate as it is found on the ocean bottom. In addition, the lack ofscratches or grooves formed in the core sample prevents the loss of apartial vacuum which is usually formed between the top end of the coresample and the top of the sampler tube. The vacuum provides anadditional holding force retaining the core sample within the samplertube. Another advantage is that the inside cutter dimension is notchanged as the sample passes from the cutter 18 through the closurevalve to the liner 16. Therefore, many of the disadvantages of the priorart are avoided.

The top end of flexible tube 20 may be connected to a support ring 22while the bottom end may be connected to another support ring 24. Eachsupport ring may be made in two annular sections so as to receive andretain an end of the flexible tube 20 therebetween thus providing forsecure retention. The upper support ring 22 may be attached to the outertube 14 by any suitable means such as by screws which may be easilyremoved to allow replacement. The other support ring 24 may be slidablyand rotatably disposed within the core sampler so as to be able to movefrom a first position in which the flexible tube is open, as shown inFIGS. 2 and 4, to a second position in which the flexible tube istwisted closed as shown in FIGS. 3 and 5.

Connected to the flexible tube 20 and the outer tube 14 is a springmeans 26 which may be in the form of a torsion spring. The spring means26 may be substantially concentric with and located between outer tube14 and the flexible tube 20 with each spring end adjacent and attachedto a respective support ring. The movement of the spring means 26 as ittranslates from a biased to an unbiased condition twists the flexibletube 20 from an open to a closed position. As shown in FIGS. 2 and 4,the spring is in a biased position, the flexible tube in an openuntwisted position; in FIGS. 3 and 5, the spring is shown in an unbiasedposition holding the flexible tube in a twisted closed position.

One of the main problems of the prior art devices is the inability toretain the core sample against the suction created when the core sampleris withdrawn from the ocean bottom. This disadvantage has been overcomein the present invention by having the core sampler automatically closeas it begins to withdraw itself from the ocean bottom. The automaticclosing is initiated by arelease means which may comprise a latch means28 operatively connected to an arm 29. The latch means 28 maycommunicate with the support ring 24 through a slot 30 in the supportring and a slot 31 in outer tube 14 located opposite the slot 36 whenthe flexible tube 20 is in an open position. The latch means 28 may be ahigh pitch threaded screw with the slots 30' and 31 having correspondinghigh pitch threads.

The arm 29 is connected to the latch means 28 and is rotatable from asubstantially upward position to a downward position. As shown in FIG.4, the arm 29 is in an upward position when the flexible tube 20 is inan open position as the core sampler is driven into the ocean bottom.Upon the initiation of withdrawal of the core sampler, soil exterior thecore sampler acts upon the arm 29 causing it to rotate to a downwardposition as shown in FIG. 5. The rotation of the arm 29 and the screwlatch means 28 causes the latch means to disengage from the support ring24. As the support ring 24 is no longer retained, the spring means 26will be free to return to an unbiased position. Under the spring meansinfluence the support ring 24 will rotate and slide to a new position asshown in FIG. 5. As the spring means translates to its unbiased positionit twists the flexible tube into a closed position. Since the rotationof the arm 29 occurs immediately upon the core sampler being raised fromthe ocean bottom, there is little likelihood that much or any of thecore sample will be lost. As shown in FIG. 5, once the valve closes, atight substantially waterproof closure is formed. The tight closureprevents any leaks which may cause the core sample to break away andfall into the ocean. If the sampler should fail to close completely thebiasing force of the spring means 26 will continue to exert a closingforce on the flexible tube so that complete closure occurs when theobstruction or excess soil falls away.

The outer tube 14 is threadedly separated at 34 so as to enable quickand easy access to the closure valve in case of repair or replacement.The connection 34 also allows the lower part of the tubular corer 12 tobe removed so as to allow the liner [16 with a core sample to be removedafter it is back aboard ship.

Operation Operation of the core sampler is extremely simple and veryreliabie. The core sampler 10 is either dropped over the side of asurface vessel or lowered into the ocean until it reaches the oceanbottom. The core sampler will penetrate the soil so as to cause a coresample to be received inside of the tubular corer 12. Once a core samplehas been achieved it is desired that the sampler be closed to preventdestruction or damage to the sample. Closure occurs when the coresampler 10 is lifted upward out of the ocean bottom. The lifting causesthe ocean sediment or soil exterior of the sampler to act downwardly onthe arm 29 causing the arm to rotate from an upward position to adownward position. The rotation of the arm 29 causes the latch means 28to disengage from the support ring 24.

Under the influence of the spring means 26 as it translates from abiased to an unbiased condition the support ring 24 will rotate andslide until the spring means 26 assumes the position as shown in FIG. 5.The rotating, sliding motion of the support ring 24 causes the connectedflexible tube 20 to twist approximately so as to ciose the tubular corer12 and retain the core sample. Tests have shown that the flexible tube20 does not go through a quick circular motion cutting through the coresample but rather goes through a progressive strangulation of the coresample column, the flexible tube pushing continuously on the bottom ofthe core sample and taking the place of that which is displaced. Hence,there is a continuous spring bias to continually tighten around thebottom of the core sample and prevent loss of the sample.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

I claim:

1. A tubular core sampler comprising:

a tubular core receiving member;

a flexible tube adjacent the lower end of and substantially concentricwith the inner surface of the tubular member and adapted to be twistedfor closing said tubular member;

spring means, one end connected to the tubular member and the other endconnected to the flexible tube, for twisting the flexible tube from anopened position to a closed position as the spring means translates froma biased to an unbiased condition; and

means connected to the tubular member for releasing the spring meansfrom the biased condition to said unbiased condition,

whereby after a core sample is taken the release means is adapted torelease the spring means which causes the flexible tube to twist andclose the tubular member.

2. A core sampler as claimed in claim 1 including:

support rings connected to opposite ends of the flexible tube and toends of the spring means, with one support ring being connected to thetubular member and the other support ring being slidably and rotatablydisposed with said tubular member.

3. A core sampler as claimed in claim 2 wherein the spring release meanscomprises:

latch means disposed inside said tubular member for releasably retainingsaid other support ring with the spring in the biased condition;

an arm rotatably mounted to the exterior of said tubular member andcapable of rotating from an upward position to a downward position withrespect to the tubular member;

said arm being operatively connected to the latch means so that thesupport ring is retained when the air is in the upward position and thesupport ring is released when the arm is in the downward position,whereby upon withdrawal of the core sampler from the ocean bottom soilexterior the sampler will act on said arm to rotate it to said downwardposition to close said tubular member.

4. A core sampler as claimed in claim 3 including:

the other support ring having a slot therein;

the tubular member having a slot which is located opposite from the slotin the support ring; and

the latch means being disposed within said tubular member slot andengaging the support ring slot when the spring is in the biasedcondition.

5. A core sampler as claimed in claim 3 wherein the spring means is atorsion spring disposed between and substantially concentric with theinner surface of the tubular member and the exterior of the flexibletube.

6. A core sampler as claimed in claim 1 wherein each support ringcomprises:

two sections adapted to retain an end of the flexible tube therebetween.

7. A core sampler as claimed in claim 1 wherein:

the spring release means includes means responsive to movement of soiladjacent the exterior of the core sampler upon withdrawal of said coresampler for releasing said spring means.

8. A core sampler as claimed in claim 1 wherein the spring means is atorsion spring disposed between and substantially concentric with theinner surface of the tubular member and the exterior of the flexibletube.

9. A core sampler as claimed in claim 1 wherein the flexible tube is anylon cloth.

10. A core sampler comprising:

a tubular core receiving member;

a flexible tube disposed adjacent the lower end of and substantiallyconcentric with the inner surface of the 6 tubular member and adapted tobe twisted from an open to a closed position;

a pair of support rings connected to opposite ends of the flexible tubewherein one support ring is attached to the inner surface of the tubularmember and the other support ring is slidably and rotatably disposedwithin said tubular member;

said other support ring having a slot;

said tubular member having a slot which is located opposite from theslot in the support ring;

a torsion spring disposed between and substantially concentric with theinner surface of the tubular member and the exterior of the flexibletube and connected at each end to a respective one of the support rings,said spring adapted to twist the flexible tube;

a latch means disposed within said tubular member slot and engaging thesupport ring slot with the spring in the biased condition;

an arm rotatably mounted to the exterior of said tubular member andcapable of rotating from an upward position to a downward position withrespect to the tubular member; and

said arm being operatively connected to the latch means so that thesupport ring is retained when the arm is in the upward position and thesupport ring is released when the arm is in the downward position,

whereby upon withdrawal of the core sampler from the ocean bottom soilexterior the sampler will act on said arm to rotate it to a downwardposition causing the spring to twist the flexible tube and thus closethe said tubular member.

References Cited UNITED STATES PATENTS 562,628 6/1896 Lester 25174 X1,582,936 5/1926 Shriver 175253 1,655,644 1/1928 Baker l75243 X1,761,292 6/1930 Bone -240 1,960,973 5/1934 Knight 25174 X 2,746,2255/1956 Cloud 2514 X 2,893,691 7/1959 Johnson 73-425 X 3,008,529 11/1961Lynch et a1. 175243 3,188,070 6/1965 Lee 2514 X 3,302,464 2/1967Langguth 175-58 X FOREIGN PATENTS 24,326 1899 Great Britain.

CHARLES E. OCONNELL, Primary Examiner.

I. A. CALVERT, Assistant Examiner.

